CN100426190C - Modifying a power management algorithm based on wireless communication parameters - Google Patents

Abstract

The wireless device determines characteristics of a connection established (or to be established) with a remote device and implements a power management algorithm based on those characteristics. The wireless device includes a battery power source, a battery powered radio transceiver, memory and a controller. The controller is configured to establish a wireless connection with the remote device via the transceiver in any of a plurality of connection configurations. The controller detects the presence of one or more parameters identifying one of the plurality of configurations in a wireless transmission from the remote device. Based on the identified configuration, the controller implements one of a number of power management algorithms.

Description

Method and device for modifying power management algorithm based on wireless communication parameters

technical field

The present invention relates to power management in electronic devices communicating over wireless links.

Background technique

Wireless communication between electronic devices over relatively short distances is a common and increasingly important feature of modern life. For example, in some cases an electronic device or other device is controlled by another electronic device that must communicate instructions to (and possibly receive information from) the device being controlled. Examples of these include computer input devices (eg, mice, trackballs, joysticks, game controllers) and remote control units (eg, for televisions or other equipment). In other cases, one electronic device must send and/or receive more complex data to and from another electronic device. Examples of these include computer keyboards, digital cameras, and other devices capable of sending data to a computer or another device. Among other advantages, transmitting data and/or control signals wirelessly can significantly increase user convenience and reduce the clutter of multiple connecting cables.

While there are several standards for wireless communication, BLUETOOTH is becoming the de facto standard for many applications. The Bluetooth wireless specification, developed by Bluetooth SIG Inc., establishes protocols and standards for two-way wireless communication between electronic devices using relatively low-power radio communications. Bluetooth consists of such as "Specification of the Bluetooth System (Bluetooth System Specification)" (version 1.1 and 1.2), "HumanInterface Device (HID) Profile version 1.0 (Human Interface Device (HID) Profile version 1.0)" and available from the Bluetooth SIG Inc. in various other documents available at <http://www.bluetooth.com>. Bluetooth provides, among other things, two-way radio links between multiple devices in a short-range radio network known as a "piconet."

As an example of a Bluetooth piconet, a personal computer may be configured to receive input from one or more wireless input devices, such as a wireless mouse and/or a wireless keyboard. In some cases, the user connects the device to the piconet simply by bringing the device within range of the computer's Bluetooth controller. In other cases, more steps may be required to bind the device to the computer Bluetooth host to authenticate the device and establish secure communication between the devices. In either case, a series of inquiries, pages, and other messages are exchanged between the input device and the computer to establish the connection through which user data (eg, mouse movements or button presses, keyboard key presses, etc.) is sent to the computer. In some cases, data from applications or other software executing on the computer is also sent to the input device through this connection. The details of exchanging messages between devices to establish a connection are described in the Bluetooth documentation referenced above and are known in the art.

To maintain the connection, messages need to be periodically exchanged between the input device and the computer even when the input device has no user data to send. In effect, the input device periodically sends an "I'm still here" message. The computer responds "OK, you're still on my list" and maintains the connection. Although the interval between user data and/or "I'm here" messages from the input device can vary, it is typically on the order of tens of milliseconds. If the computer does not receive a message from the input device before the timeout period expires, the computer assumes that the input device is turned off or is not present and disconnects (or "delists") the connection to the device. In order for the input device to communicate with the computer again, another series of messages must be exchanged to re-establish the connection.

This can cause conflicts with design requirements for wireless input devices such as computer mice or keyboards. Since wireless devices are battery powered, it is desirable to reduce the power consumption of the device as much as possible to extend battery life. The radio transceiver that communicates with the controller consumes a lot of power from the device. Neglecting other considerations, when the device is idle, that is, when the device is not actually communicating user data with the computer, the period between transfers should be kept as short as possible. However, if the interval between transmissions is too long, the connection to the computer can be lost. Although a connection can be reestablished, such reestablishment is relatively time consuming and increases the time required for user input (eg, moving a mouse) to elicit an appropriate response from the computer (eg, moving a cursor).

This input-response delay, or latency, is noticeable to humans if it is on the order of 100 milliseconds or more. The acceptable amount of perceived latency varies with different conditions and with different users and usage styles. For computers and input devices operating under an earlier version (1.1) of the Bluetooth specification, the time to reestablish the connection is on the order of 1 second or more. Under version 1.2 of the Bluetooth specification, the reconnection time was reduced, and in some cases, this time could be reduced to about 250 milliseconds. This is a significant improvement and in some cases results in acceptable latency. Under other conditions, this can still result in excessive latency. However, the Bluetooth specification allows manufacturers to incorporate additional features into a Bluetooth-compliant device (whether it is a computer, input device, or other device), as long as these additional features do not prevent the device from providing certain other features necessary for Bluetooth compliance. feature. As a result, manufacturers are able to develop Bluetooth specification-compliant chipsets that provide a faster reconnection process than the Bluetooth specification's "default" connection process.

Unfortunately, the benefits of the faster Bluetooth version 1.2 and proprietary reconnection process are unrealizable in many cases. For example, a computer mouse may be equipped with the hardware and firmware necessary to implement a proprietary fast reconnect process, but the mouse may be used on a computer that does not support the fast reconnect process. If used with a computer that supports the fast reconnect process, the mouse implements a power management algorithm that suspends radio communication with the computer for a period of time that causes the mouse-computer radio connection to be lost. When data needs to be transferred to the computer (eg, the user moves the mouse after a period of no mouse use), the connection can be re-established quickly enough to avoid (or minimize) any perceived latency. However, this power management algorithm may result in unacceptable latency if the mouse is used with a computer that does not support the fast reconnect process.

Various systems and methods are known for automatically detecting the protocol used by a device to communicate with a computer. US Patents 6,442,734 and 5,754,890, assigned to the assignee of the present invention, are two examples. However, neither these patents nor other known prior art describes optimizing (or modifying) power management algorithms based on parameters of communication links between devices, especially wireless communication connections.

Contents of the invention

Embodiments of the present invention allow a wireless device to determine characteristics of a connection established (or to be established) with a remote device, and then implement a power management algorithm based on these characteristics. In one embodiment, a wireless device includes a battery power supply, a battery powered radio transceiver, memory and a controller. The controller is configured to create a wireless connection with the remote device through the transceiver in any of a plurality of connection configurations. The controller detects the presence of one or more parameters identifying one of the plurality of configurations in a wireless transmission from the remote device. Based on the identified configuration, the controller implements one of a plurality of power management algorithms.

These and other features and advantages of the present invention will be more clearly and fully understood when read in conjunction with the following detailed description of the preferred embodiments in conjunction with the accompanying drawings.

Description of drawings

Figure 1 is a diagram of a computing system environment implementing at least one embodiment of the present invention.

FIG. 2 is a side cross-sectional view of the mouse of FIG. 1 .

FIG. 3 is a block diagram of the circuitry of the mouse of FIGS. 1 and 2. FIG.

Figure 4 shows a state diagram for an example power management algorithm.

Figure 5 is a state diagram of another example power management algorithm.

Figure 6 shows the transmission of protocol data units to a wireless mouse.

Figure 7 shows the transmission of protocol data units to the wireless keyboard.

8 is a block diagram of circuitry of a wireless keyboard in accordance with at least one embodiment of the present invention.

Figure 9 is a state diagram of a wireless computer input device in accordance with at least one embodiment of the present invention.

Figure 10 is a state diagram of a wireless computer input device in accordance with another embodiment of the present invention.

Detailed ways

The present invention provides systems and methods by which a wireless device can detect information about a communication link with another device and then adopt or modify a power management mode. The invention is described by way of example of a desktop computer and a wireless computer input device communicating under the Bluetooth standard. However, the invention is not limited to these particular types of devices or the Bluetooth standard. The invention may also be implemented in numerous other general purpose or special purpose computing system environments or configurations, with other types of devices, and in devices that communicate via other wireless communication standards and/or protocols.

Figure 1 illustrates one example of a suitable computing system environment in which the present invention may be implemented. Shown in side view in FIG. 1 is a desktop 2 with a monitor 4 and a keyboard 6 . Also shown is a wireless mouse 100 which communicates with the computer 2 via an RF transceiver within a dongle. The dog 8 is connected to a USB or other port of the computer 2 and is located on the outside of the computer 2 (as shown). In at least one embodiment, dongle 8 houses the electronics and firmware required to accept Bluetooth communications from and send Bluetooth communications to a remote device such as a mouse or keyboard. In at least one embodiment, components within dongle 8 convert received Bluetooth data into a format that can be passed to computer 2 through the USB port, and similarly convert USB data into a format that can be sent over the Bluetooth link. Specifically, the dog 8 contains the components and firmware required to implement the computer 2's radio, baseband link manager and L2CAP Bluetooth layer. In other embodiments, the electronics and firmware for enabling Bluetooth communications may be internal to the computer 2 and connected directly to the system or other bus without an intervening USB connection.

FIG. 2 is a side cross-sectional view of mouse 100 . Mouse 100 may have one or more buttons 102 that can be pressed by a user, a scroll wheel 104, or other types of input controls that can be operated by a user. The number, arrangement and types of input controls shown are exemplary only, and other combinations and permutations are also within the scope of the invention. The operation of switches, scroll wheels, and other types of input controls are known in the art and thus will not be further described here. Mouse 100 may also have one or more internal circuit boards 106 or other substrates on which various electronic components are connected and physically supported. These components may include imaging array 108 , LED or laser source 110 , RF antenna 112 , controller 114 , and battery/power supply 126 . Other components not shown in FIG. 2 may include memory and other electronic components. LED or laser source 110 emits light that illuminates an area of the tabletop or other surface, which is imaged by imaging array 108 . The images from array 108 are then compared to detect movement of mouse 100 on a tabletop or other surface.

FIG. 3 is a block diagram of the internal circuitry of the mouse 100 according to a preferred embodiment of the present invention. Operation of the mouse 100 is controlled by a microprocessor (μP) controller 114 . Although controller 114 is shown as a microprocessor, controller 114 may alternatively include state machine circuitry or other suitable components capable of controlling the operation of mouse 100 as described herein. Controller 114 is in communication with memory 116 . Memory 116 may include volatile and non-volatile memory, which is a machine-readable medium for storing software (or firmware) instructions, imaging data, and configuration settings (such as power management algorithms discussed in more detail below). Memory 116 may include rewritable non-volatile components such as battery-backed SRAM or EEPROM, and/or non-rewritable components such as ROM. Controller 114 also controls LED or laser source 110 ( FIG. 2 ) and imaging array 108 ( FIG. 2 ) and other imaging elements, all collectively represented by block 118 . Controller 114 also controls RF communication circuitry 120 and communicates data to RF communication circuitry 120 for transmission to computer 2 via antenna 112 (FIG. 2). Similarly, data communicated to mouse 100 is received by antenna 112 ( FIG. 2 ) and RF circuitry 120 and sent to controller 114 . Controller 114 communicates with imaging element 118 , RF circuitry 120 , and memory 116 via one or more buses 122 (collectively shown as bold double-headed arrows). Controller 114 also receives electrical signals corresponding to user manipulation of mouse buttons 102 (FIG. 2), scroll wheel 104 (FIG. 2), or other input controls. These electrical signals are collectively represented by user input 124 . The various electronic components of mouse 100 are powered by power supply 126, which may include one or more batteries.

Although FIG. 3 shows controller 114, imaging circuitry 118, RF circuitry 120, and memory 116 as discrete components, this need not be the case. For example, one or more of these components may be contained within a single integrated circuit (IC) or other component. As another example, the controller 114 may include internal program memory such as ROM. Similarly, the functionality of these components described herein may be distributed across additional components such as multiple controllers or other components.

The present invention allows the mouse 100 to automatically implement a power management algorithm based on the parameters of the wireless Bluetooth connection to the computer 2 . For explanatory purposes, two simplified power management algorithms are presented. However, it is understood that devices according to other embodiments of the present invention may have additional and/or more complex power management algorithms.

A first power management algorithm 200 is shown in the state diagram of FIG. 4 . In the active state 202, the mouse 100 is configured for immediate use. In other words, the active state 202 assumes that the user is currently moving the mouse, pressing a mouse button, or providing input to the computer 2 with the mouse 100 . Controller 114 causes LEDs 110 (FIG. 2) and imaging array 108 (FIG. 2) to rapidly create an image. The controller 114 also causes the RF circuit 120 to send periodic messages containing data to the computer 2 (via the dog 8), or to maintain a connection with the computer 2 .

After 1 second of no user activity, mouse 100 transitions to idle state 204 . As used herein, "no activity" includes a situation where the user is not using the mouse to provide user data to the computer 2 . In other words, the user did not move the mouse, press a mouse button, or spin the scroll wheel. In some embodiments, mouse 100 is equipped with a proximity sensor (not shown) capable of detecting the presence of a user's hand on or near mouse 100 . In such embodiments, mouse 100 may be configured to treat non-proximity of a user's hand as an "inactivity" condition. In idle state 204, controller 114 causes LEDs 110 (FIG. 2) and imaging array 108 (FIG. 2) to create images at a reduced rate. Controller 114 also reduces the rate at which RF circuit 120 sends messages to computer 2 . Specifically, the messages are only sent at intervals short enough to ensure that if the user moves the mouse 100, presses a mouse button, or continues to restart the mouse 100, the latency is not noticeable. Since the mouse 100 is in the idle state 204, no user data is to be sent to the computer 2. If there is mouse motion or other user activity while in the wait state 204, the corresponding user data is sent in the next scheduled idle state transmission, after which the mouse 100 returns to the active state 202. In one embodiment, RF messages are sent to computer 2 in idle state 204 at a rate of one message every 70 milliseconds. If the mouse 100 senses activity (eg, movement, button press, hand proximity) within 10 minutes after entering the idle state 204 , the mouse 100 returns to the active state 202 . After 10 minutes of inactivity, the mouse 100 enters an extended idle state 206 . When entering the extended idle state 206, the controller 114 sends a message to the dog 8 to terminate the connection; After that, the dog 8 terminates the connection with the mouse 100 . In the extended idle state 206, the controller 114 disables the RF circuit 120 and no longer transmits to the computer 2 (or listens for transmissions from it). The imaging rate is also further reduced. Mouse 100 returns to active state 202 upon sensing movement, button press, hand proximity, or other indication that the user desires mouse 100 . If the connection to computer 2 has been terminated, the connection must be re-established between (or as part of) returning to active state 202 .

FIG. 5 shows a second power management algorithm 220 . Active state 222 is similar to active state 202 of algorithm 200 (FIG. 4). Imaging components (LEDs 110 and imaging array 108) and RF circuitry 120 are rapidly activated. After 1 second of inactivity, the mouse 100 transitions to the idle state 124 . Similar to idle state 204 of algorithm 200, the imaging and RF transmission rates are reduced. However, unlike algorithm 200 , mouse 100 remains in idle state 224 for a shorter period of time before transitioning to extended idle state 226 . In one embodiment, the mouse 100 transitions back to the active state 222 if activity is detected within 1 minute in the idle state 224 . If no activity is detected after 1 minute, the mouse 100 transitions to the extended idle state 226. Similar to the extended idle state of algorithm 200 , in extended idle state 226 controller 114 disables RF circuit 120 and no longer transmits to (or listens for) transmissions from computer 2 . Mouse 100 returns to active state 222 after user activity is detected. Upon entering the extended idle state 226, the mouse 100 terminates the connection with the dog 8 and must re-establish the connection before returning to the active state 222 (or as part thereof).

As can be understood from the description above, the algorithm 200 allows the mouse 100 to disable the RF circuit 120 more quickly, thereby saving power. However, this comes at the cost of re-establishing the connection to computer 2 more frequently. If it takes too long to re-establish the connection, the user will perceive the time between when he or she attempts to resume input with the mouse 100 and when the input is confirmed by the computer 2 . In some cases, this is just an annoyance, while in other cases, this can actually lead to data loss (eg, mouse clicks may not be detected by computer 2, and the user may come to realize this non-detection) .

Thus, as further illustrated with FIG. 6 , mouse 100 selects between power management algorithms 200 and 220 based on one or more parameters of the connection established between mouse 100 and computer 2 . When the connection between the mouse 100 and the computer 2 is initially established, a series of messages are transmitted between the mouse 100 and the dog 8 . The content, format, sequence and other details of these messages are described in the Bluetooth documentation referenced above, and thus are not further described here. As part of these messages, various link manager (LM) protocol data units (PDUs) 300 are sent from the dongle 8 to the mouse 100 . Contained within one or more of the PDUs 300 is data identifying features supported by the dog 8 and/or computer 2. Many of these features are specific to versions 1.1 and 1.2 of the Bluetooth standard, or as many may be supported by dongle 8 and/or computer 2. For example, Adaptive Frequency Hopping (AFH) is a feature supported by Bluetooth version 1.2, but not version 1.1. If the Dogdog 8 is a Bluetooth version 1.2 device, it can enable AFH by issuing (within PDU 300) the LMP_set_AFH command. If the mouse 100 receives this command, the controller 114 determines that the computer 2 is communicating via the Bluetooth version 1.2 standard.

In at least one embodiment, the default reconnect time for Bluetooth version 1.2 is within acceptable limits for mouse 100 latency. For example, mouse 100 may be designed (or configured) for use by individuals who prefer to accept some degree of latency in return for longer battery life. In this embodiment, the controller 114 is programmed to implement the power management algorithm 220 after detecting parameters indicative of a Bluetooth version 1.2 connection to the computer, and to implement the power management algorithm 200 otherwise. In another embodiment, the mouse 100 is designed (or configured) for users who do not wish to accept some degree of latency associated with the default reconnect time of Bluetooth version 1.2. However, in this embodiment, mouse 100 is also equipped with hardware and/or firmware that permits mouse 100 to reconnect faster than the default Bluetooth version 1.2 connection time, as long as the connection is made with the same hardware and/or hardware as required. firmware for another device build. In this embodiment, the controller 114 implements the power management algorithm 220 if the mouse 100 receives a PDU 300 from the dog 8 indicating that the dog 8 has the required hardware and/or firmware. Otherwise, mouse 100 implements power management algorithm 200 .

As noted above, the present invention is not limited to computer mice. Fig. 7 shows a computer keyboard 6' according to another embodiment of the present invention. FIG. 8 is a block diagram of the internal circuitry of the keyboard 6' according to one embodiment of the present invention. The operation of the keyboard 6' is controlled by the microprocessor 152. The microprocessor 152 scans for one or more key presses (or releases) by scanning the key conductor matrix 154, and upon detection of a key press (or release), causes the appropriate on or off code to be sent by the RF circuit 156 . Microprocessor 152 is also in communication with memory 160 on which power management algorithms 200 and 220 are stored. The microprocessor 152 and other components of the keyboard 6' are powered by a battery 158. In one embodiment, the microprocessor 152 implements the power management algorithm 220 after receiving the PDU 300' (FIG. 7) instructing the computer 2 to communicate via Bluetooth version 1.2. Otherwise, the microprocessor implements the power management algorithm 200 . In another embodiment, the keyboard 6' is also equipped with hardware and/or firmware that allows the keyboard 6' to reconnect faster than the default Bluetooth version 1.2 connection time, as long as the connection is made with the same hardware and/or hardware as required. or firmware built for another device. If the keyboard 6' of this embodiment receives a PDU 300' from the dog 8 indicating that the dog 8 has the required hardware and/or firmware, the microprocessor 152 implements the power management algorithm 220. Otherwise, the keyboard 6' implements the power management algorithm 200.

FIG. 9 is a state diagram of a controller of an input device, such as controller 114 of FIG. 3 or microprocessor 152 of FIG. 8 , configured to operate in accordance with at least one embodiment of the present invention. FIG. 9 combines certain aspects of FIGS. 4 and 5 . In state 301, the controller establishes (or re-establishes) a connection with another Bluetooth device. When initially establishing a connection, the controller receives one or more PDUs providing connection parameters. In state 302, the controller determines which power management algorithm to implement based on the parameters identified in state 301. If the connection parameter corresponds to a connection type that supports enough blocks of connection re-establishment, then the first (more power efficient) algorithm is implemented. Specifically, the controller places the input device into active state 304, which is similar to active state 222 (FIG. 5). After 1 second of inactivity, the controller transitions the input device to idle state 306 , which is similar to idle state 224 of FIG. 5 . If activity is detected within 1 minute in idle state 306 , the input device transitions back to active state 304 . If no activity is detected after 1 minute, the input device transitions to the extended idle state 308 . Similar to the extended idle state 226 of the algorithm 220, the controller disables the RF circuitry and no longer transmits to (or listens for transmissions from) the remote device in the extended idle state 308. Upon detection of user activity, the controller transitions the input device to state 301 and establishes or re-establishes a connection. If it is determined in state 301 that the connection is a reestablished connection with the same remote device, then the various connection parameters (which were previously received when the connection was initially established) are not resent, and the input device transitions directly from state 301 to state 304. If the connection is to another remote device, connection parameters for the new remote device are received, and at state 302 it is determined whether the newly connected remote device supports sufficiently fast connection re-establishment. If so, the input device transitions to state 304 again.

If at state 302, after initially establishing a connection with the remote device, it is determined that the parameters of the just established connection do not correspond to a connection type sufficient to support fast re-establishment of the connection, then a second algorithm (less power efficient) is implemented. Specifically, the controller places the input device into the active state 310, which is similar to the active state 202 (FIG. 4). After 1 minute of inactivity, the controller transitions the input device to idle state 312 , which is similar to idle state 204 of FIG. 4 . If in the idle state 312 , and activity is detected within 10 minutes, the input device transitions back to the active state 310 . If no activity is detected after 10 minutes, the input device transitions to the extended idle state 314 . Similar to the extended idle state 206 of the algorithm 200, the controller disables the RF circuitry and, in the extended idle state 314, no longer transmits to (or listens for transmissions from) the remote device. After detecting user activity, the controller transitions the input device to state 301 and establishes or re-establishes a connection. If the connection is a reestablished connection with the same remote device, the input device returns directly from state 301 to active state 310 .

Figure 10 is a state diagram of a computer input device according to another embodiment of the present invention. Similar to state 301 of FIG. 9 , the controller of the device according to FIG. 10 establishes (or re-establishes) a connection with another Bluetooth device in state 401 . As part of establishing the connection, the controller receives one or more PDUs providing connection parameters. In state 402 , and similar to state 302 of FIG. 9 , the controller determines which power management algorithm to implement based on the parameters identified in state 401 . However, in the embodiment of FIG. 10, the controller selects from three or more power management algorithms 404, 406, 408, and so on.

While specific examples for implementing the invention have been described, those skilled in the art will appreciate that there are many variations and permutations of the above systems and techniques that fall within the spirit and scope of the invention as set forth in the claims. These and other modifications are within the scope of the invention as defined in the appended claims.

Claims (13)

1. A device for automatically selecting a power management algorithm, characterized in that it comprises: a battery power supply; a radio transceiver powered by said battery and having components for transmitting and receiving data; a memory on which instructions are stored; and a controller coupled to the transceiver and memory configured to execute the instructions to: establishing a wireless connection with a remote device via said transceiver in any one of a plurality of connection configurations, Detecting, in a wireless transmission from a remote device, the presence of one or more parameters identifying one of the plurality of configurations by determining whether the wireless connection with the remote device has a configuration corresponding to an acceptable at least one parameter of the fast reconnect procedure, and Based on the identified configuration, one of a plurality of power management algorithms is implemented. 2. The device of claim 1, wherein the controller is configured to: After determining that said at least one parameter exists, implementing a power management algorithm in which said transceiver is deactivated after a first period of device inactivity, and After determining that the at least one parameter is absent, implementing a power management algorithm in which the transceiver is deactivated after a second period of device inactivity, the second period being longer than the first period. 3. The device of claim 2, wherein the controller is configured such that if the device is not being used to generate or transmit data based on input from a human using the device, the device is inactive. 4. The device of claim 1, wherein the controller is further configured to detect the presence of the one or more parameters when establishing a wireless connection with a remote device. 5. The device of claim 1, wherein the plurality of power management algorithms comprises three or more power management algorithms. 6. The device of claim 1, wherein the device is a computer input device. 7. The device of claim 6, wherein the device is a computer mouse. 8. The device of claim 6, wherein the device is a computer keyboard. 9. A method of automatically selecting a power management algorithm in a battery powered wireless device capable of establishing a wireless connection with a remote device in any one of a plurality of connection configurations, comprising: Establish a wireless connection with a remote device; determining wireless communication features supported by the remote device; implementing a first power management algorithm if the remote device supports a first communication feature; and implementing a second power management algorithm if the remote device does not support the first feature, Wherein the first communication feature includes supporting an acceptable fast reconnection procedure. 10. The method of claim 9, characterized in that: the first power management algorithm includes deactivating the transceiver after a first period of wireless device inactivity, and The second power management algorithm includes deactivating the transceiver after a second period of wireless device inactivity, the second period being longer than the first period. 11. The method of claim 10, wherein the wireless device is inactive if the wireless device is not being used to generate or transmit data based on input from a user. 12. The method of claim 9, further comprising: A third power management algorithm is implemented if the remote device does not support the first feature but does support the second feature. 13. The method of claim 9, wherein said determining wireless communication characteristics comprises determining wireless communication characteristics when establishing a wireless connection with a remote device.

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